I made an iPhone app and exported it with phone gap. It uses iAd object, gamecenter object, and IAP object. The ipa file runs very smoothly on my phone and on several other devices so I suspect that the IAP or leaderboards from gamecenter are causing the issue. When I try to use the IAP while testing, a message Sprite I created shows up indicating that the purchase failed so I think the IAP works fine. The leaderboards sometimes shows the leaderboard but it doesn't let me sign in on test mode or on my phone. I urgently need help. Thanks.